Graphic: Wildfires raging in North America

Hundreds of wildfires are raging in British Columbia, Alberta, Quebec and the Northwest Territories while the U.S. is battling large blazes in Arizona, Nevada, Utah, Idaho, California, Colorado, Florida, Washington state and New Mexico. Canada has already had more than 2,000 wildfires this year. And this week saw U.S. President Barack Obama ask Congress for $615-million to help fight the fires this season. So where are the hotspots in North America and how do those fires start and spread?